Carbureter.



K. B. BRITTON.

CARBURETER.

APPLICATION HLED SEPT. 28.1914.

Patented Apr. 9

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Application filed September 28, 1914. Serial No. 863,845.

To all whom it may concern:

Be it known that I, KARL B. Bnrrron, a citizen of the United States, residing at .Cleveland(,) in the county of Cuyahoga and State of bio, have invented a certain new and useful Improvement in Carbureters, of which the following is a. full, clear, and exact description.

The object of this invention is to provide a, cheap carbureter which, when connected with an internal combustion engine, will supply thereto a mixture of air and hydrocarbon vapor of substantially uniform proportions, re or load of t e engine.

The invention consists in the construction and combination of parts hereinafter described and pointed out definitely in the ap ended claims.

the drawing Figure 1 is a plan view of a carbureter embodying the invention, and having a horizontal air.tube,said air tube and the parts therein being shown in central horizontal section. 'Fig. 2 is a vertical section of the same carbureter,-the section being in the plane of line 2-2 on Fig. 1. Fig. 3 is a side elevation of a carbureter embodyin the invention and having a .vertical air tu e;--said air tube being shown in vertical section. Fig. 4 is a plan view of the same carbureter with the air tube shown in horizontal section in the plane of line 44 on Fig. 3; and Fig. 5 is a vertical section of a part of the air tube,-said section being in the plane of line 55 on Fig. 4..

Referring to the parts by letters, A represents the air tube of the carburetor. This is of the usual venturi form, and has a single air inlet opening at one end, and is provided at its open discharge end with a flange a to facilitate its connection with the mixture inlet pipe of the engine. This tube contains, adjacent to its discharge end, a throttle valve C which, as shown, is of the usual butterfly form, but may be of any desired foam. And this throttle valve governs the rate of flow of the explosive mixture from the carbureter to the engine.

I) represents a constant level fuel reservoir,that is to say, a float chamber of any usual or suitable construction which is adapted for connection with a fuel tank.

B represents the nozzle which extends dia- Speclflcation of Letters Patent.

rdless of changes in the speed a 2B. BBI'LTON, OF CLEVELAND, OHIO, ASE IGNOR TO THE BBITTON OABB'U'B E OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

- UBETEB.

Patented Apr. 9, 118.

metrically across the most restricted art of the Venturi tube A, and is so mounted in the walls thereof that it may be turned in its bearings to the extent necessary, as hereinafter set forth. Onel end 6 of the nozzle pro ects through the wall of the air tube and is made square, or otherwise so shaped as to facilitate the turning of the nozzle for adustment purposes. A duct 6 extends longitudinally into the nozzle from the opposite end thereof and to a point adjacent to the center of the air tube. The open end of this duct is in communication with the fuel chamber D. As shown in Fig. 2 the nozzle extends through a wall of the air tube, which is also a wall of the fuel chamber, to a point where it is in open communication with the fuel in said chamber. As shown in Fig. 5 the open end of the nozzle duct 6 communicates with a duct 03 formed in the wall of the fuel chamber and opening at its lower end into the fuel chamber below the level of the fuel therein. The fuel discharge jet opening I) is a radial hole drilled in the nozzle'and communicating at its inner end with the fuel duct b. The nozzle must be set in such position that this jet opening is directed at an angle, which I have found by actual use should be substantially 45 degrees, toward the inlet end of the air tube, and therefore against the air stream which flows through the air tube from the open inlet end thereof toward the flanged discharge end thereof,the direction in which the air stream flows being shown by arrows in Figs. 1, 3 and 5. While actual use has demonstrated that the angle of 45 degrees is the angle at which the best or most nearly perfect results are achieved, yet it is possible that moderate variations from this angle may be made without destroying the useful function of the device, and in fact, it may be possible to achieve better proportioning results when so varied than are poswhich are that constitutes the fundamentally novel characteristic of the described carbureter,

and makes it possible to produce the desired results without using any of the several kinds of auxiliary proportioning devices nerally found in carbureters.

Itmay' e desirable to variably restrlct the size of the duct through which the fuel through the described flows from the float chamber to the jet opening. 4 In the construction shown in 2 this may be accomplished by a nee e valve E which screws longitudinally mto the nozzle so as to extend to a greater or less 20 degree over the inner end of the jet open ing. Or as shown in Fig. 5 aneedle valve E may be screwed down through the wall of the float chamber into the ductd. It will, of course, be understood that the discharge endof the jet 0 enin is above the level of the fuel in the cat c amber.

The flow of fuel from the float chamber ducts and out of the jet opening 6 into the air tube may be said to be caused by the atmospheric ressure on the fuel in the float chamber; an it may be said that such flow is opppsed by the air open end of the air tube pressure in the air tube. hen. the engine, to which the carbureter is attached, is not running, these pressures are equal, and

therefore there is no flow of fuel from the jet opening. But whenthe engine is running, on each suction stroke a partial vacuum is created in the air tube,that is to say, there is a reduction of static pressure therein.,fA's a result, the air rushes into the but never at a sufficient rate to. completeiy fill the vacuum. Inother words, the static air pressure in the air tubeis reduced on said suction strokes and this results in the flow of fuel from the float chamber out of the jet opening into the air tube, where it vaporizes and becomes mixed with the inrushing air. The wider open the throttle valve, the more rapid W111 be the flow of. air into and through the air tube, and the greater will be the reduction of staticpressure of the air in said air tube, and consequentl the higher will be the rate of fuel flow. .iVith nearly all carbureters which have attained any practical and commercial success, and which ave been constructed without auxiliary proportioning devices, the rate of flow of fuel has increased more rapidly than the rate of flow of air past the nozzle. Therefore the resultin mixture grows progressively richer as t e engine speed increases.

The carbureter sh wn in the drawing and heretofore explaine is unique in that it is promotes.

self proportioning because the fuel jet opening 1s directed at an angle, as stated, against the inrushing air stream.

The flow of fuel from a nozzle which dis-,

charges into the air tube of a carbureter is affected 'not only by the change in the statlc pressure in the air tube,thatis to say, the change in the static head of the air in said air tube, but it is also affected by the change in the velocity head of the flowing air stream. As the speed or load of the engine is increased the static head of the air in the air tube is decreased, and this, obviously, re sults in an increase in the rate of flow of the fuel. But as the static head of the air stream is decreased, the velocity head is increased. With the carbureter herein shown and described, the jet opening is directed against the flowin air stream and the increased velocity hea tends to op ose the increase in the rate of fuel flow which the decrease in the static head of the air I have discovered that when the jet openin is dis osed, as shown in the drawing and as erein efore described, in the direction of about45 degrees against the flowing air stream, the stated reverse chan es in the velocity head and the static hea of the flowing air stream, which occur when the speed or load of the engine is varied, have such counterbalancing effects upon the flow of fuel as will cause the maintenance of a Sub. stantially constant ratio between the fuel discharged from said jet opening and air flowing through the air tube.

Having described 111 invention, I claim:

1. In a carbureter, t e combination of an air tube of fixed dimensions, a fuel nozzle having a jet opening through which fuel may flow from said nozzle into said air tube -which jet opening is constructed to source of fuel supply with which said nozzle communicates.

2. In a carbureter, the combination of an air tube adapted for connection at its, outlet end with the mixture inlet pipe of an internal combustion engine and having an air inlet opening of invariable size adjacent its other-end, a fuel nozzle havin a fuel jet opening arranged to discharge mto the air tube at an angle of approximately 45 toward the inlet end of said air tube and without any contra-disposed openings, and a source of fuel supply with which said nozzle is connected.

3. In a carbureter, the combination of an air tube having an outlet adjacent to one end which end is adaptedifor connection with bustion engine, and having adjacent to its the mixture inlet pipe of an internal 'comretiree other end an-air inlet whose efiective area is invariable during difierent running conditions of the associated engine, a fixed nozzle which projects into said air tube between the inlet and outlet openings thereof,-which nozzle is constructed with all its discharge area positioned in'a direction at an angle of about 45 a ainst the air stream flowing through said air tube, and a constant level fuel chamber with which said nozzle is in communication, and a valve for varying the size of the opening through which fuel may flow into said nozzle from said fuel chamber.

4. A carbureter for internal combustion engines comprising an air tube and a fuel through said air tube, whereby the discharge 20 of fuel from said fuel nozzle is automati-' cally regulated by the velocity of the air passing through said tube, substantially as set forth.

In testimony whereof, I hereunto a my 25 signature in the presence of two witnesses.

KARL B; BRITTON. Witnesses L. l. PORTER, A. J. HUnsoN. 

